AD4115 with switched power-supplies

Question

Hi, I want to use the AD4115 with switched power-supplies. Do they have negative impact on accuracy? 
 The application is a Battery Management System (BMS), sampling every second voltage, amperes and temperatures. During main of that second, the current used b the BMS should be at low as possible. A switched power-supply (i.e. MAX25232 or LM33630, or a AD alternative not searched for yet) can operate in High Efficiency with low load. 
 The most accuracy needed is measurings amps during charge or load, from some mA up to 200A.

andreialejandro · Accepted Answer

Hi, 
 It is possible to use switched power supplies with the AD4115. Note that the impact of this configuration is that the switched power supplies contribute noise to the analog input and digital lines of the ADC and lessen the accuracy of the ADC. To solve this issue, you can add LDO regulators between the switching supply and the ADC. 
 https://www.analog.com/en/products/power-management/ldo-linear-regulators/ldo-plus.html 
 Regards, 
 Andrei)

JellenieR · Answer

Hi, 
 I guess it depends on the target noise performance/accuracy and also depends on the switching frequency. For example, does the switching frequency will alias into ADC input bandwidth or sampling rate? Ideally, a switcher is not recommended for high precision lower bandwidth sigma delta ADCs as it may introduce noise error or interference in the measurement system. But like I said it depends on your target resolution or accuracy, in some cases having a good circuit and layout design of the switcher may minimized the error effect on its neighboring component but the first thing to check really is the switching frequency and its possibility in aliasing to ADC's input and sampling frequency. 
 Thanks, 
 Jellenie

pno · Answer

Hi, 
 Again, thanks for your answer. I take the advice and do testing with an extra LDO.

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AD4115 with switched power-supplies